Excess flow check valve with manual reset means



INVENTOR. 0.L. GARRETSON BY% 5 2 g g ATTORNEYS Oct. 27, 1953 o. GARRETSON EXCESS FLOW cnacx VALVE WITH MANUAL RESET MEANS Filed April 15, 1946 Patented Oct. 27, 1953 EXCESS FLOW CHECK VALVE WITH MANUAL RESET MEANS Owen L. Garretson,

Bartlesville, kla., assignor to Phillips Petroleum Company, a corporation of Delaware Application April 15, 1946, Serial No. 662,371

This invention relates to excess flow valves. In one particular aspect it relates to excess flow valve mechanisms having manually operable means for resetting such valves.

One preferred use to which this invention is adapted is an internal excess flow valve for liquid petroleum gas containers, but the invention is not limited to such use. It may be employed in any application to which excess fiow valves are adapted.

The use of excess flow valves of conventional design on outlet lines of liquid petroleum gas containers has the great disadvantage of permitting small leaks in outlet lines between the excess flow valve, usually installed at the junction of outlet line and container, and the terminal hand valve with which such lines are conventionally closed. A partial breakage or development of a small leak in such location is not sufficient to cause an excess flow valve to close but may result in serious explosion or fire hazard and also may waste much valuable material. An excess flow valve which may be manually reset when desired is needed for use on liquid petroleum gas trucks.

It is an object of this invention to provide an automatic excess flow valve mechanism which may be manually operated to reset the valve when desired.

Another object is to provide an automatic excess flow valve mechanism which is simple. rugged, foolproof and cheap in construction, and which has the particular advantageous arrangement and combination of parts as shown.

Other objects and advantages will become apparent to those skilled in the art as this disclosure proceeds.

My invention may be better understood on reference to the accompanying drawings wherein the figure is a vertical section of a preferred embodiment thereof.

In the figure valve body having a fluid conduit 6' therethrough is shown in two-piece construction inserted into a double walled containing vessel .1, 'I' and 1A is sealed olT at some place (notshown). Valve seat I I is disposed in conduit 6, having outlet port 8 and inlet ports 9. A moveable valve head I2 is disposed in conduit 5' and is adapted to be moved to seat on valve seat II, thereby substantially closing conduitt. Valve stem I 4' is attached to valve head I2 and extends slideably through end closure :member IE. Resilient member I5 is adapted to be compressed when valve head I2 is raised from seat II' and exerts pressurefitending to seat head I 2' on seat II. Any simple mechanical means for constantly xerting controlled pressuremay be substituted for member I5.

A threaded rod extends through threaded IA. Obviously the space between 3 Claims. (Cl. 137-460) end member l9 into conduit 6' and is adapted to be advanced and retracted in a direction perpendicular with the plane of valve head I 2' by turning hand wheel 2 I. Rod 20' is made sufliciently long to force head I2 from seat II when the rod is fully advanced. Rod ZO'carries resilient member 25. Moveable housing 26 surrounds rod 20' and resilient member 25. This housing is adapted to be guided by rod 20' and to be advanced toward valve head I2 by pressure of resilient member 25 and to be forced back by pressure suiiicient to compress resilient member 25. Member 2'! carried by rod 20' limits the movement of housing 26 in the direction of valve head I2. Extension member 28 may be attached to housing 25, for example, being threaded thereto by threads 29, and adapted to force valve head I2 away from valve seat II when rod 20' is advanced, to the position shown in the figure. Obviously, extension member 28 may be made integral with housing 26if desired.

While 'I" and IA are shown as a double wall, obviously the valve structure of the figure may be applied to a single wall structure.

Operation The embodiment shown in the figure is installed in a containing vessel I, IA and connected to an outflow pipe (not shown). With the valve head seated on valve seat II' pressure of fluid within the containing vessel and pressure from member I5 retainvalve head I2"on seat II against pressure transmitted from resilient member 25 via housing 26 tending to raise the valve head from the valve seat. To open the valve hand wheel 2| must be turned to advance the threaded rod 20 to raise valve head I2 slightly from seat II. Fluid then flows into conduit 6' and pressure therein builds up sufiiciently to permit pressure from resilient member 25 transmitted via the housing 26 to raise valve head I2. Rod 20' is thenretracted slightly below the level of eat II. I 1

In the open position the valve functions as an excess flow valve; Excess flow through conduit 6' reduces the backpressure on valve head I 2" and permits the valve head tobe forced into seating position on seat I I by combined pressure of fluid within containing vessel I, IA and from member I5 against I resistance of member "25. When closed the valve must be opened by manually operating hand wheel 2I to advance rod 29'. It will be noted that the closure member I6 defines a chamber together with the upper part of conduit 5' and valve head I2 when the valve is in open position, and the fluid inlet ports 9 are positioned between said chamber and thevalve seat II. The seating face of the valve head is thus so positioned relative to the flow path of fluid through the valve that, when there is an is produced by the viscous drag of the fluid flowin from inlets 9 to outlet 8 ag'ainst housing 25. This force tends to move housing 25 downwardly and thus reduce the upward pressure of the housing against the valve head. 7

While I have shown in the drawing an illustrative embodiment of my invention, obviously means adapted: to exerton. said valve head tending-1 to. move the, same to seat on said valve seat; and manually operable means for moving said valve head from said valve seat comprising, in combination, a threaded rod disposed in saidconduit adapted to be advanced and revarious modifications may be made in the same without departing from the spirit or substance of the invention which is defined in scope only byth following claims.

Ha'l"i1g described my invention, I claim:

1. An. excess flow valve comprising, in combination; a valve body having av fluid conduit therethrough; a. valve seat disposed in said conduit; a moveable valve head disposed in said conduit adapted to be moved to seat on said valve seat and thereby close said conduit; the edges of said valve. headbeing closely spaced to said conduit and defining a restricted passage therewith, means closin said conduit at the end thereof remote. from said valve seat, thereby defining a chamber together with the conduit and valve when the valve,- is in open position, a fluid inletpositioned between said chamber and said valve seat, the seating face of the valve head being so positioned relative to the flow path that, upon excess flow, the resulting reduction in pressure will act upon said seating face to produce a pressure differential'tendingto cause closure of the valve, a valve stem attached to said valve head and slideably extending through said body; a. first spring disposed within said chamber adapted to exert pressure on said valve head to move said valve head to seat on said valve seat; and means for moving'sai'd valve head from said valve seat thereby opening saidconduit comprising; in. combination, a threaded: rod extendingthrough; said body; adapted to be; advanced and retracted: by turning}; a, housing slideable with respect-to said rod and engageable with said valve head; a second spring; withinsaid housing havin one end: thereof; secured to? said rod and theothgr end thereof secured to said housing so as to.- urge said housinginto; engagement withthe valve head: and open; saidv valve, said valve head be ing :moved from, open position to closedposition when; the combined-..for.ce due to. said first spring nd-tdfmw pastsaidopcnv lve exceeds the openmg; iq ceof the second spring.

. 2.. In an excess; flow. valve, in? combination; a valve bodyhaving a; fluid conduit therethrough; a valve seat disposed in said conduit; a moveable valve head. disposed in. said conduit adapted: to bemoved: to. seat on. said valve. seat: andthereby close. said conduit; the; edges; of said valvehead being closely spaced; to; said conduit. and defining a, restricted passage therewith, means closing saidconduita-t the end thereor-remotef-rom said valve seat, thereby clefininga chamber together with the; conduit and; valve head. when. the. valve isin open; position, a. fiuijd inlet. positioned between said chamberand; said. valve. seat; the seating face of: the valve; head. being so positioned relative. to;- the flow paththat, uponl excess flow; theresulting reduction, inpressure. willact upon said ting. face. to; produce a. pressure differential tending tdi yilsfiicloduifeiof the valve, mechanical tracte'd by turning, a rigid member slideably mounted with respect to said rod and engageable with said. valve head, biasing means including a spring having oneend thereof connected to said. rigid member and the other end thereof connected to said rod to urge said rigid member into engagement with the valve head and open the valve, said valve being moved from open position to closed position when the combined. force: due to said mechanical means. and. to flow past said open valve exceeds the-opening force of said biasing means.

3. An excessfiow valve mechanism comprising, in combination; a body having a fluid conduit therethrough; a valve seat disposed in said conduit; a rnoveable'v valve head disposed in said conduit. having its. edges closely spaced to the Walls of said conduit and defining a restricted passage therewith, said moveable. valve head being adapted to seat on said valve seat and thereby close said conduit; means. closing said conduit at the end thereof remote from said valve seat. thereby defining. a chamber together with the conduit and valve head when the valve isin open position, av fluid inlet positioned between said chamber and said. valve-seat, the seating. face. of the valve head being so. positioned relative to the flow path that, upon excess flow, the resulting reduction in pressure will act upon said seating face to produce a pressure differential tending to cause closure of the valve, resilient means for exerting pressure on said valve head tending to move the same to seat on said valve seat; and manually operable means comprising, in. combination, a rod. disposed in said conduit adapted to be advanced and retracted, a housing slideable with respect to said rod and adapted to engage said valvev head, a resilient member having one end thereof connected tosaid rod and the other end thereof connected to said housing so as to urge said housing into engagement with the valve hea'd andthereby open thevalve, saidvalve being movedirom anopen position to. av closed position when the combined force due to. said resilient means and to flow past said open valve. exceeds the opening force of said resilient member.v

1... GARRETSON References Cited in. the, file of this patent UNITED STATES PATENTS 

